When it is desired to use a pet door with a set of sliding doors, a common arrangement is to mount the pet door in a long panel (which may be height-adjustable), and then insert the long pet door panel at one end of the sliding door frame opening. The pet door panel is secured to the sliding door frame, and the abutting sliding door is latched to the pet door panel. Such an arrangement is illustrated in U.S. Pat. No. 4,408,416 to the applicant. Conventional latching arrangements for the sliding doors may be inadequate for security purposes when such an arrangement is adopted, however. If the latch for connecting the panel to the sliding door is too simple, a rod or stick manipulated by someone through the pet door might be able to operate it.
It is therefor an object of the invention to provide an adequate security knob on a pet door panel added to a sliding door arrangement.